As is well known in the art, cylinder locks generally include a plug (also called tumbler) arranged for rotation in a cylinder lock housing. Plug pins are slidingly disposed in the plug and are arranged to move against driver pins, which are disposed in bores formed in the cylinder lock housing and are spring biased toward the axis of the plug rotation. Insertion of a properly cut key in a keyway provided in the plug moves the plug pins against the driver pins and aligns all the pins along a shear line defined by the plug outer circumference, thereby permitting rotation of the plug to cause operation of a latch or locking mechanism.
In the prior art, insertion of the key brings all the plug pins to the shear line before rotation of the plug.